The present invention relates to an air bag mounting system for motor vehicles and, more particularly, to a steering wheel for vehicles, particularly designed to have light weight and high rigidity and adapted to be easily equipped with an air bag unit used for security purposes in emergencies.
There have been proposed various kinds of steering wheels with the air bag unit to eliminate or reduce shocks given to the driver when the vehicle collides with another vehicle or structure such as a building. For this purpose, the air bag unit is mounted on the center of the steering wheel of the vehicle.
In one conventional example, an air bag module mount is provided on the steering wheel, and formed by die casting. In another example, the air bag module mounts made by an aluminum die-casting are secured to spokes connecting respective corner portions of a central boss plate and the steering wheel. Japanese Pat. Laid-open Publication (KOKAI) No. 54-93531 published July 24, 1979 discloses a steering wheel of the type described above.
However, the steering wheel of the above described type requires air bag module mounting members, made by die-casting, which are secured to the spokes by welding, so that assembly work is not easy.
Furthermore, the force applied to the driver operating a vehicle when it collides against another vehicle or a structure such as a building, is transmitted to the steering wheel through the air bag, so that it is necessary to make the spokes, particularly the upper ones highly rigid. To the contrary, the steering wheel must be made as light as possible for easy handling.